Cisco Warns of New Zero-Day ISE Auth Bypass (CVSS 10.0) Exploited in Active Attacks

Cisco has identified a severe security flaw in its Identity Services Engine that is being actively exploited. The vulnerability allows an unauthenticated remote attacker to bypass authentication due to insufficient control on an API endpoint. This flaw has a CVSS score of 10.0, indicating a maximum severity level. Cisco has assigned the vulnerability the identifier CVE-2026-76460. The issue makes it possible for an attacker to gain unauthorized access without proper authentication. An attacker can exploit this vulnerability remotely.